Improved oxidation resistance of Cr-Si coated Zircaloy with an in-situ formed Zr2Si diffusion barrier
Song Zeng, Junfeng Li, Chen Chen, Yan Meng, Chaowen Zhu, Xiaochun Han, Yiwang Bao, Haibin Zhang
Abstract
Abstract In the present study, the dense Cr and Cr 0.92 Si 0.08 coatings have been deposited on Zircaloy-4 substrates by the magnetron sputtering technique. The high-temperature oxidation resistance of coatings is evaluated in 1200 °C steam for 1–4 h. The Cr 0.92 Si 0.08 coating shows better oxidation resistance than the Cr coating. The in-situ formed Zr 2 Si diffusion barrier inhibits the mutual diffusion of Cr and Zr. And the formation of a Cr 2 O 3 /SiO 2 double-layer scale effectively improves the oxidation resistance of a single Cr 2 O 3 layer. The formation of the in-situ diffusion barrier, Cr 2 O 3 /SiO 2 scales and oxidation protection mechanisms of the Cr 0.92 Si 0.08 coating have been discussed in detail.